Author: Nat Pernick, M.D. (see Authors page)

Revised: 17 November 2015, last major update August 2015

Copyright: (c) 2003-2015,, Inc.

PubMed Search: bcl-XL[title]
Definition / General
  • Longer transcript of bcl-X
  • Protects cells from apoptosis (i.e. anti-apoptotic marker)
  • Relative amounts of pro- and anti-survival Bcl-2 family of proteins determine if cell will undergo cell death - if more Bcl-xL is present, pores are non-permeable and the cell survives (Wikipedia)

Signal transduction pathways

Clinical Features
  • Cytoplasmic staining; colon carcinoma cells serve as positive control
Uses by Pathologists
Micro Images

Images hosted on

Diffuse large B cell lymphoma (fig F)

Ba: compound nevus is negative
Bb: melanoma >1.0 mm thick (times 400) is strongly positive
Bc: subcutaneous metastasis is positive

Positive Staining - Normal